The present invention relates to a three-phase collected type optical current transformer in which the optical transformers corresponding to three phases are incorporated in a common hermetically sealed container miniaturized in its radial direction.
One of such previously known three-phase collected optical current transformers is disclosed in JP-A-H-2-69672. In this conventional transformer, three branch tubes or flanges which protrude from the common hermetically sealed container incorporating three-phase central conductors in its radial direction were used to construct the optical current transformer corresponding to each of three phases.
The conventional three-phase collected type optical current transformer constructed in the above manner has disadvantages that its design is complicated since the flanges corresponding to three phases must be formed in the common hermetically sealed container and the container is large-scaled in its radial direction due to the optical current transformer to be connected with each of the flanges.